Such changes were precisely why Komlos said he compared and contrasted the NHANES numbers. He had noticed the beginnings of this trend in past research, and only found enough data to show a shrinking stature among black women in the October study.
"They (the CDC) collect millions of data on different kinds of information from blood pressure to whatever have you," Komlos said. "Height is not something that is of particular interest to them, it seems to me."
However, even Komlos thinks there is more research and analysis to be done to determine what the height disparity found in his study might mean.
For example, why the height decline, the study found, is mostly among the lower and middle income group.
Ellen Gruenbaum, a professor and head of the anthropology department at Purdue University, was also curious about how income levels shaped Komlos' findings.
"Statistics kept by imprecise categories like 'race' often reflect what are really socioeconomic and lifestyle differences," she said. Height, health and socioeconomic status are definitely connected, she added.
Considering that black men have grown taller in recent generations, and now measure an average of a third of an inch shorter than white men, according to Komlos' study, Gruenbaum hopes researchers follow up with studies about earlier puberty for girls and neighborhoods that promote or do not promote exercise.
"Higher socioeconomic classes generally have safer environments, better schools, more parks and safer streets for play, exercise, walking to school, etc," Gruenbaum said in an e-mail to ABCNews.com. "Dangerous neighborhoods, by contrast, lead to children -- especially girls, perhaps -- staying inside more for safety."